1. Field of the Invention
This invention relates to industrial-size water cooling towers, and especially to crossflow towers of generally circular configuration. The invention is particularly useful for rehabilitating hyperbolic cross-flow water cooling towers that have been in use for a period of time to cool the condenser cooling water of power plants or the like.
2. Description of the Prior Art
Electrical generating power plants utilize cooling towers to cool water that is directed to a steam condenser forming a part of the steam generating and condensing portion of the plant. In the case of very large electrical generating plants, concrete hyperbolic cooling towers have found favor because the airflow required for cooling of the hot water which gravitates through the fill assembly of the tower may be induced by the natural draft effect of the hyperbolic stack. This avoids the necessity of utilizing part of the electrical energy generated by the power plant to energize induced draft fan motors that would otherwise be required.
Counterflow, as well as crossflow, hyperbolic cooling towers for power plants have been built and are in operation. Each has its own advantages and disadvantages. One important advantage of a crossflow type tower is the fact that the hot water distribution basin is open, thereby making it easier to maintain the distribution system, as compared with a counterflow tower where the hot water distribution nozzles are buried deep within the tower immediately above the fill structure.
In the case of crossflow towers, however, one problem that has arisen involves icing of the inlet faces of the fill assemblies, thus resulting in consequential damage to the fill components. Damage principally occurs when the ice partially melts and is released from the fill components for fall toward the underlying cold water basin. The ice that is allowed to fall toward underlying fill components damages such components by impact of ice thereagainst.
Many of these concrete crossflow hyperbolic cooling towers have now been in operation for a sufficient number of years that tower performance has decreased because of general deterioration of the fill over time. Furthermore, in those geographic climes where freezing weather is encountered during the winter, damage to the fill assembly as a result of icing of the fill face can be substantial.
In view of the significant initial cost of concrete crossflow hyperbolic towers, it has been difficult to increase the performance of such towers because of the difficulty of modifying the overall structure of the towers. Efforts to minimize fill damage resulting from icing of the fill faces have also met with limited success and acceptance.
For the most part, rehabilitation of circular crossflow, industrial-size water cooling towers, whether of the hyperbolic stack or mechanical draft type, has been limited to replacement of the fill components. Although this restores the performance of the tower to a level approaching that of the original design, the rehab does not increase the performance of the tower over the initial level, and furthermore does very little to mollify the icing problems that previously existed.